Filament package



April 30, 1968 R. L. WASHBURN 3,380,577

FILAMENT PACKAGE Filed April 10, 1967 l INVENTOR ROBERT mm WASHBURN ATTORNEY United States Patent 3,380,577 FILAMENT PACKAGE Robert Latham Washburn, Vienna, W. Va., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del., a corporation of Delaware Filed Apr. 10, 1967, Ser. No. 629,582 3 Claims. (Cl. 206-46) ABSTRACT OF THE DISCLOSURE Unraveling of filaments on the inside of a spoolless package is prevented by the insertion of an inflatable membrane, for example, a balloon within the package.

Recent developments in the packaging of filaments include a package formed solely of filaments by selected windings of the filaments to produce a coil which does not require a spool for support. Packages of this type are described in United States Patents 2,634,918, 2,725,- 197, 2,767,938, 2,828,092 and 3,178,130 and are referred to hereinafter as spoolless packages.

The spoolless packages of the present invention are adapted for withdrawal of the filament from the core of the package through the side without twist or through either end with twist. The filaments in such a package may be unwound quite rapidly. When the spoolless packages were shipped, a portion of the filaments which defined the core space of the package was loosened and became entangled resulting in a birds-nest eflect within the core. This tangled material had to be removed before the remainder of the filament could be removed from the package.

The present invention is directed towards the elimination of the tangled filaments in spoolless packages and is realized by providing a flexible, elastic membrane inserted into the core of the package and inflated to contact the filaments which define the inner surface or core of the package. This membrane prevents the formation of tanglements within the core during handling and shipping by holding the filaments in place and can be removed after deflation and before any filaments are withdrawn from the package.

A more complete understanding of the present invention may be had by referring to the drawing attached hereto and made a part of the present specification in which FIG. 1 is a top plan view of one of the preferred embodiments of the package of the present invention; and FIG. 2 is a cross section along the line 22 of FIG. 1. In FIG. 1, the arrangement of the present invention may be seen. A monofilarnent 3 is wound to form a cylinder 4 which contains a core 5 extending therethrough. The monofilarnent is wound and arranged to be Withdrawn from the center 6 of the cylinder 4 through a channel 7 in the side of the package. The entire cylinder 4 is covered with a film which serves to restrain the outer surface 8 and also the upper and lower surfaces of the elastic membrane 9. It is convenient to provide an opening 10 in the film to permit insertion of the inflatable membrane if desired after application of the film. In FIG. 2, the arrangement of the inflatable membrane within the cylinder 4 can be seen. The membrane 9 bears against the inner surface 6 of the cylinder and against the upper and lower surfaces 11 and 12 of the restraining film. Prior to the removal of the filament through channel 7, the membrane 9 may be punctured and removed through opening 10.

The following example is presented to illustrate but not to restrict the present invention.

3,389,577 Patented Apr. 30, 1968 A filament made from 6-10 nylon and having a diameter of approximately 12 mils is wound into a cylindrical package having an internal diameter of approximately 8 inches, an external diameter of approximately 11 inches and a height of 6 inches, according to procedures known in the art of which the following is a brief description.

A spooling machine, spindle driven, is arranged with a base wind ratio of 4 (this ratio is the number of turns of the spindle divided by the number of turns of the traverse cam and is an even number). The traverse cam is driven by an appropriate program as described in the patents mentioned hereinabove and provides for generation of a radial hole from the center to the outside of the package approximately midway in the package. A segmented collapsible chuck is employed which permits easy removal of the wound package. This spooling unit is run in line and when the package has reached the desired outside diameter, the spooling machine is stopped. The outer or running end of the filament is tied to prevent unwanted movement. The inner end is inserted through the radial hole and secured. The completed package is covered with a film of shrinkable polyethylene and heat applied causing the film to shrink tightly around the outer surfaces of the package and across the opening in the hollow core. A hole is provided on one surface of the shrunk film adjacent the core through which a balloon approximately 3 inches in diameter is inserted and inflated with air until the balloon contacts substantially all of the inner surface of the core space. The balloon is then tied oif and the entire package placed in a carton for shipment. Upon receipt of the supported package, it is noted that none of the filaments which define the core of the package is loosened, whereas the filaments in the core of the package subjected to similar conditions but without the internal support were tangled sufficiently to require removal of the tangled portion before the filament could be unwound from the package. The tangled portion amounted to approximately 10% of the filament.

The present invention is applicable to the packaging of all types of filaments made from a variety of polymers such as polyamides, polyesters and polyolefins and the like. The outer film or core surrounding the package may be made from heat-shrinkable polyethylene as ill-ustrated or from some other suitable heat-shrinkable thermoplastic material such as cellulose acetate, polyvinyl chloride, polypropylene and polyesters as well as from paper and the like.

The inflatable membrane of the present invention is made from elastomeric materials such as rubber; however, one skilled in the art will appreciate that other types of moderately elastic film be substituted for the rubber described hereinabove.

Generally, the inflatable membrane should completely fill the core space of the spool. The pressure level within the membrane will vary upon the filament diameter and the degree of package stability that is reequired.

I claim:

1. A package of thermoplastic filament comprising a winding of a filament in layers in the form of a cylinder having a core space longitudinally therethrough, said filament arranged to unwind from the core space, a film surrounding and constraining the filament on the outer surface of said cylinder and a flexible elastic membrane inflated with gas thereby contacting the filament defining the core space and the film contiguous to said space.

2. A filament package consisting essentially of at least one filament of a flexible material wound in inner-meshed layers to form a cylinder having an annular core space, said filament arranged to unwind from the core space, a

3 4 film surrounding and constraining the outer surface of References Cited said cylinder and a flexible deflatable gas-containing UNITED STATES PATENTS membrane occupying substantially all of said core space 0 and constrained by the filament defining said core space 3,260,358 7/ Gomly et a1 206 46 and by the film contiguous to said space. 5 FOREIGN PATENTS 3. The package of claim 2 wherein said filament is a 910,271 4/1954 Germany.

filament of polyhexamethylene adipamide and said film made from Polyethylane' MARTHA L. RICE, Primary Examiner. 

